﻿/*
* Copyright (c) 2010-2012 Tesla Engine Group
* 
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
* 
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
* 
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/

using System.Collections.Generic;
using Tesla.Math;

namespace Tesla.Bounding {
    /// <summary>
    /// Comparer that compares the distances of two intersection records.
    /// </summary>
    public class IntersectionComparer : IComparer<IntersectionRecord> {

        /// <summary>
        /// Compare the two intersection records.
        /// </summary>
        /// <param name="x">First record</param>
        /// <param name="y">Second record</param>
        /// <returns>-1 if x's distance is less than y's, 0 if they are about the same,
        /// or 1 if x's distance is greater than y's</returns>
        public int Compare(IntersectionRecord x, IntersectionRecord y) {

            //Account for floating point error, if just about equal then return 0
            if(MathHelper.FuzzyEquals(x.Distance, y.Distance)) {
                return 0;
            }

            if(x.Distance < y.Distance) {
                return -1;
            } else {
                return 1;
            }
        }
    }
}
